https://doi.org/10.1140/epjd/e2007-00152-3
Structure and dynamics of cationic van-der-Waals clusters
III. Binding and structure of ArnHCl+ clusters
1
Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, 14476 Golm, Germany
2
Hahn-Meitner-Institut, Abteilung SF5, Glienicker Straße 100, 14109 Berlin, Germany
Corresponding author: a zuelicke@tc1.chem.uni-potsdam.de
Received:
18
January
2007
Revised:
22
March
2007
Published online:
11
May
2007
ArnHCl+ van-der-Waals clusters for n = 1–13 are investigated
with the “minimal diatomics-in-molecules (DIM) model”
using ab-initio input data obtained from multi-reference
configuration-interaction calculations plus subsequent projection onto
valence-bond wavefunctions.
The results for the complexes with n = 1–3 are checked against
ab-initio calculations at the
coupled-cluster (CCSD) level with the same one-electron atomic basis set as
for the input data generation (aug-cc-pVTZ from Dunning).
In addition to the electronic ground state,
the first excited 
state for the triatomic
complex (n = 1) is also studied.
The results
from the DIM model are shown to be in fair agreement with those from
advanced conventional ab-initio calculations, although there are
differences in detail. The comparison
justifies the extension of the DIM approach to n > 3.
Systematic analysis of the local minima of the multi-dimensional
potential-energy surfaces (PESs), carried out with the combined
method
described in part I (Monte-Carlo sampling plus subsequent steepest-descent
optimization), reveals simple building-up regularities for the most
stable structures (i.e. those corresponding to the global PES minimum)
at each n: apart from always having a nearly linear
(Ar–H–Cl)+ fragment as core, the aggregates show little
or no symmetry. Secondary local minima are also determined and their
structures interpreted.
The PESs for the low-lying excited states reveal a much more complicated
topography compared to the ArnH+ clusters allowing a variety
of photo-processes.
The energy level sequence of the first five excited electronic states
and the stability of the clusters in these states is studied
as a function of the cluster size n.
PACS: 31.15.Ar – Ab initio calculations / 31.50.Bc – Potential energy surfaces for ground electronic states / 31.50.Df – Potential energy surfaces for excited electronic states / 36.40.-c – Atomic and molecular clusters / 36.40.Wa – Charged clusters / 36.40.Qv – Stability and fragmentation of clusters
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007
